Diarrhea and acute respiratory infections account for nearly 30% of deaths among children displaced due to humanitarian emergencies, with diarrhea causing up to 40% of child deaths in acute emergency settings. Intense crowding and acute and chronic malnutrition contribute to the high burden of diarrhea and acute respiratory infection. Sanitation infrastructure can be overwhelmed quickly with the influx of displaced persons and water quality can be poor, contributing to the high diarrhea risk. Repeatedly, handwashing has been shown to be infrequent at times relevant to pathogen transmission. But, there is a wealth of evidence supporting the impact of handwashing promotion for prevention of both diarrhea and acute respiratory infections. Provision of soap to a refugee population has been shown to lead to maintenance of soap in the home, and fewer episodes of diarrhea in households with soap in the home. Water scarcity represents a critical barrier to handwashing with soap and water, particularly in the displaced persons' camp setting. Maintaining water for handwashing in small containers is a constant challenge, particularly when handwashing facilities are shared amongst unrelated households. The hectic nature of life in a displaced persons' settlement may further challenge adherence to handwashing with water and soap at various critical times. Waterless hand sanitizer has been adopted widely in high-income settings because of its efficiency, convenience, and elimination of the need for water. Many waterless sanitizers contain alcohol but alternative options, such as chlorhexidine gel, have similar antimicrobial efficacy and may be more acceptable to some populations with religious or cultural proscriptions against alcohol. In the humanitarian emergency context, a waterless method of improving hand hygiene could overcome water supply concerns, require less frequent replenishment than water, and represent an efficient method of hand cleansing at critical times. Moreover, waterless hand sanitizer can be efficiently distributed as part of hygiene kits. In the context of an ongoing humanitarian emergency, we propose to evaluate the acceptability of two formulations of waterless hand sanitizers, and to measure the impact of provision and promotion of waterless hand sanitizer on hand cleansing behavior and effectiveness for prevention of diarrhea morbidity and mortality. We will use qualitative research methods to investigate the acceptability and barriers to use of alcohol-based and non-alcohol based waterless hand sanitizers. We will distribute the most acceptable formulation in a displaced persons' settlement and evaluate uptake and impact of sanitizer uptake on diarrhea morbidity. Using a case-control study approach, we will evaluate the association between sanitizer uptake and diarrhea mortality. This innovative study will inform public health approaches to prevent unconscionably high rates of diarrhea mortality among young children affected by humanitarian emergencies.